U.S. Pat. No. 4,769,278 discloses a method for forming a cast molded part incorporating an outer skin layer of thermoplastic material backed by a layer of foamed material formed by casting a resin powder with foam constituents against the inner surface of the outer skin layer.
U.S. Pat. No. 4,900,489 discloses a method for forming a skin foam article that includes preparing a preformed and fused skin from a resinous material and thereafter forming a second layer of expanded and fused layer of resinous material on the inner surface of the skin.
U.S. Pat. No. 3,555,130 disclose a molded article of microcellular urethane in which either a urethane quasi-prepolymer system or a one shot urethane system is directed into a mold surface to form an integral urethane skin that is substantially non-porous.
None of these patents discuss a method for casting a mixture of thermoplastic particles against the heated surface of a mold to simultaneously form an integral non-porous skin backed by a thin layer of foam suitable for use as a preformed cover for use in forming interior trim articles for automobiles and for use in other articles requiring a relatively non-porous good wearing outer surface combined with a soft feel.